Rockrider E-st 900 changes upgrades

[Zimmerframe]

All in all I'm very pleased with the tyre choice and going from 2.8 to 2.4 seems to be better on this bike.

I think this is much the same on any bike. 2.8+ was the "big" thing .. There are probably lots of circumstances when they're fantastic.

It also has to be said, when you see a bike in the shop with 2.8's - as a man, for some reason it says "buy me" ..

You see them less and less now on higher end bikes. I think I have a load in a garage I should try to give away quickly whilst someone might still want them

 

[chamaruco]

Here you see the connections of the Brose-T engine.
2-pin wheel sensor below.
5-pin for HMI somewhat higher.

Anybody knows what the other connections are for ?
It think, the 2 above are 6V for front- and back light, but there seems to be another 5-pin (?) below.

View attachment 38992

does it help? https://www.decathlon.co.uk/p/brose-c85440-101-front-bike-light-cable/_/R-p-200096
https://www.decathlon.co.uk/p/brose-c86130-100-rear-bike-light-cable/_/R-p-200097 see the diagram illustrated
from dedicated decathlon page https://www.decathlon.co.uk/p-a/e-st-900-electric-mountain-bike-grey-275/_/N-0?mc=8487240

 

[Gary Davis]

Has anyone ever thought of using the wheels of the e-st520 to fit thinner tires. Indeed, they are 23c and therefore they allow widths (ERTRO) between 37 and 62 compared to the original ones (60-75)

 

[DT36]

Has anyone ever thought of using the wheels of the e-st520 to fit thinner tires. Indeed, they are 23c and therefore they allow widths (ERTRO) between 37 and 62 compared to the original ones (60-75)

I think this could work. I have a 520 here and the rims are noticeably thinner.
Back wheel is fitted with 9 gears on the 520.
Front wheel has a quick release fitted, but the bottom of the forks (Rockshox XC30) has lugs at the bottom, where as the Rockshox Judy fitted on the 900 has a through bolt/maxle.

However, that said, I took my bike over some heavy stones and through low river beds yesterday and the 2.40 tyres were fine on the original 900 rims. Totally understand what your saying if you want to go smaller again, but this 2.40 combination seems to match ok and definitely performed well for my riding standards. Note: this is not very high...

 

[Zimmerframe]

There's quite a few threads on Rim's and tyres ... ok .. more than quite a few

This was a recent one with a nice link in to some tyre/wheel size guidance ..

Kenevo Gen1 - 2019 Kenevo 2.8 to 2.6 tire bottom bracket height

My rear tire went kaput on my last ride. Thinking of switching to maxxis dhf/dhr 2.6 profile but concerned about the bottom bracket height

www.emtbforums.com

 

[Gary Davis]

I think this could work. I have a 520 here and the rims are noticeably thinner.
Back wheel is fitted with 9 gears on the 520.
Front wheel has a quick release fitted, but the bottom of the forks (Rockshox XC30) has lugs at the bottom, where as the Rockshox Judy fitted on the 900 has a through bolt/maxle.

However, that said, I took my bike over some heavy stones and through low river beds yesterday and the 2.40 tyres were fine on the original 900 rims. Totally understand what your saying if you want to go smaller again, but this 2.40 combination seems to match ok and definitely performed well for my riding standards. Note: this is not very high...

View attachment 53884

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View attachment 53886

Thanks. I hadn't noticed that the front wheel was not boost type. Too bad for a spare wheelset with different tyre profile

 

[Ale78c]

e-st900 Mullet 29”/27,5”

 

[chamaruco]

proud to be the inspiration...

 

[Gary Davis]

The Rockrider e-st 900 has a 34t chainring and a 11-42t cassette.

This 34t is much too short.
(Official: I drive sometimes very long asphalt downhill where electrical assistance isn't needed but where I drive faster than 27 km/h)

I measured around somewhat. The original 34t chainring has long teeth, so the new longer will have that too.
It seemed a 42t could fit.

The 34t came off without dismanteling something else.
It needs some positioning and some minor force, but it works.

The 42t is a cheapo Aliexpress thing. I prefered to spend 6eur instead of 50eur for this compatibility test.
You see the result: 1mm clearance.
The plastic chain guide doesn't fit anymore. I will have to 3D-print a similar one.

The 114link chain is too short now. I will not use the biggest ring of the cassette till the new E10 - X10E 136link chain arrives.

View attachment 38994

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View attachment 38996

Hi,
I tried to disassemble the original chainring but I finally gave up. When you say "minor force" you mean it can bend a bit ? I felt like I was going to twist it. I understand what you mean about positioning. it's annoying because the one from aliexpress seems so much easier to assemble/disassemble.

 

[RonnieX]

I couldn’t do it with ‘minor force’ either! So I bought a SuperB TB1069 lock ring tool to do the job properly.

 

[Gary Davis]

I hope I'll have a little more time off next week to make these modifications.
Shimano brakes 6120
Shimano pedals M820
seatpost (spring) XLC SP-05 Pro
mudguards SKS
stem (same as Bebiker)
I will then post some images

 

[Gary Davis]

I couldn’t do it with ‘minor force’ either! So I bought a SuperB TB1069 lock ring tool to do the job properly.

I think that's exactly what I'm going to do

 

[Gary Davis]

Has anyone ever noticed that when you turn the handlebars all the way to the left, the display cable is very tight ? So I moved it a bit to the right which also makes it easier to change power assistance with the thumb.
I know that some of you will answer "I never turn to the left !"

 

[BeBiker]

Hi,
I tried to disassemble the original chainring but I finally gave up. When you say "minor force" you mean it can bend a bit ? I felt like I was going to twist it. I understand what you mean about positioning. it's annoying because the one from aliexpress seems so much easier to assemble/disassemble.

I know what you mean, but unfortunately the positioning is impossible to explain with only a keyboard.
It felt like bending, but without being bent permanently when it came off...
In the worst case, you can cut, saw or disc the chainring away, you won't want it anymore.
The bigger one goes on without effort, like you already saw.

 

[BeBiker]

Shimano brakes 6120

I am satisfied with the mystery "Tektro TKD32" brakes, below 35 km/h
Will you keep the 180mm or go bigger ?

 

[Gary Davis]

I know what you mean, but unfortunately the positioning is impossible to explain with only a keyboard.
In the worst case, you can cut, saw or disc the chainring away, you won't want it anymore.
The bigger one goes on without effort, like you already saw.

Anyway, thanks for all your tips. I just ordered the tool mentioned by RonnieX . I will certainly use it later. As for the brakes, BR6120 are the best quality/price and mostly "good looking" . I bought 203mm Formula rotors.

 

[Gary Davis]

I was a little bit worried about the rear brake but it fits perfectly with the adapter. I also received this

73.66￡ |Support De Réparation De Vélo À Domicile, Mécanique De Vélo Portable Pour Vtt, Outil De Réparation De Vélo De Route, Support De Sol En Alliage D'aluminium - Atelier De Vélo Repaire Stand - AliExpress

Achetez malin, vivez mieux! Aliexpress.com

fr.aliexpress.com

wich will help me a lot.
Sorry in French !

 

[BeBiker]

... I bought 203mm Formula rotors.

As the E-st900 originally already has brake adapters, that fit for the 180mm rotors, I guess you now need others/aditional adapters.

I'm a little lost here:

Adapters

Purchase everything your bike needs in the Brakes - Adapters category in our shop.

www.bike-components.de

Are the mounting points on every bike the same, so you just need to know brakes-model and rotor diameter ?

 

[Gary Davis]

As the E-st900 originally already has brake adapters, that fit for the 160mm rotors, I guess you now need others/aditional adapters.

I'm a little lost here:

Adapters

Purchase everything your bike needs in the Brakes - Adapters category in our shop.

www.bike-components.de

Are the mounting points on every bike the same, so you just need to know brakes and rotor diameter ?

You're absolutely right. I've already checked which adapter I need.
Front : https://www.bike-discount.de/en/formula-adaptor-front-203mm-postmount-6
Rear : Adaptor rear 203mm IS 2000

 

[Gary Davis]

And the icing on the cake :

Monolitic 6-bolt Disc Rotor

Product features - Monolitic Disc Rotor 6-hole Use: MTB Model: One-piece Disc: 6-bolt Diameter (choose variant) 160mm 180mm 203mm Material Stainless steel Color Silver Scope of delivery...

www.bike-discount.de

 

[chamaruco]

Wait wait wait...rear you have the 180 adapter from tektro and it works with shimano..on front wheel you need the 203 adapter. That's it

 

[Gary Davis]

Wait wait wait...rear you have the 180 adapter from tektro and it works with shimano..on front wheel you need the 203 adapter. That's it

No.For the rear, the Tektro adapter doesn't work because I upgrade from 180 to 203
Sorry if I forgot to mention that I'll put 203mm rotors front and rear.

 

[DT36]

I couldn’t do it with ‘minor force’ either! So I bought a SuperB TB1069 lock ring tool to do the job properly.

I couldn't get the chain ring off and didn't have the tool to pull the crank arm off. I had it changed by a local repair shop near where I work for £5, which was cheaper than buying a puller.
I didn't consider that the new chain ring would slip on easier though. If I did, I think I would have run my disc cutter through the old one.
The 38t chain ring is much better when fitted. We did a 13 mile ride yesterday and at no point did it negatively affect me on steep hills. I have a 200m, very steep hill at the start of our ride that I can still pull in 3rd gear, which I also did on the 34t chain ring.
Speed on a long flat road used to max out about 22mph, now I'd say its about 27/28mph.

 

[Gary Davis]

I chose Formula parts because many shimano parts weren't available and also because it's a reliable brand.

 

[chamaruco]

Ok...bytheway on rear 180 it's enought

 

[Gary Davis]

Ok...bytheway on rear 180 it's enought

You're absolutely right but it's so nice

 

[chamaruco]

Uh you can challenge the boar to the death ??

 

[Gary Davis]

I couldn't get the chain ring off and didn't have the tool to pull the crank arm off. I had it changed by a local repair shop near where I work for £5, which was cheaper than buying a puller.
I didn't consider that the new chain ring would slip on easier though. If I did, I think I would have run my disc cutter through the old one.
The 38t chain ring is much better when fitted. We did a 13 mile ride yesterday and at no point did it negatively affect me on steep hills. I have a 200m, very steep hill at the start of our ride that I can still pull in 3rd gear, which I also did on the 34t chain ring.
Speed on a long flat road used to max out about 22mph, now I'd say its about 27/28mph.

You're lucky guy. Here in Brussels, local repair shops are much more expensive. Mostly during this period

 

[Gary Davis]

I'm awaiting my cummins engine but both adapters and silent-blocks aren't available for de moment.?

 

[Gary Davis]

I couldn’t do it with ‘minor force’ either! So I bought a SuperB TB1069 lock ring tool to do the job properly.

Just received it. £12. Waiting for time-off to make all modifications.